The Washington University Medical Scientist Training Program at Washington University in St. Louis was established in 1969, and has been continuously funded by the NIH since 1970. It has trained 658 MD-PhDs, more than any program in the nation. As it has been since the program's founding, our primary goal is to identify, train, and mentor a diverse group of women and men who will become leaders biomedical research, patient care, and medical education. To that end, we have designed a flexible, individualized training pathway that emphasizes the integration of clinical and research training. The University's substantial commitment to the program is evident not only in providing 68% ($8.6 million in FY2018) of the total MSTP budget, but also in tailoring the curriculum and policies to accommodate the unique requirements of MD-PhD training. Appointments to this T32 are typically made for the first 3 years of training. We are able to leverage each of the grant?s 44 training slots by a factor of 4.4 through university and other funds, which allows us to support a current population of 192 students. To select individuals to train in the program, we focus primarily on academic achievement, research experience, and a commitment to a research career. Students typically train in the Division of Biology and Biomedical Sciences, a trans-university consortium of 11 doctoral programs, but a significant number train in other academic units, including Biomedical Engineering. The 156 training faculty for this proposal are out of a total population in these academic units of over 570 tenure-track faculty. Policies are in place to select faculty for participation in graduate training, and training faculty are reviewed every 5 years. Our program enjoys strong interactions with other programs at Washington University for training of physician-scientists after they receive their doctorates, i.e., Physician-Scientist Training Programs (PSTPs) in our clinical residency and fellowship programs. Student attrition is low and has declined significantly over the past 10 years. Time to degree has stabilized at 8.0 years, and is lower than the national average. Outcomes data shows that 78% of those that have completed postgraduate training are employed by academic institutions, research institutes, federal agencies, and biotech or pharmaceutical firms. Many have research support from the NIH or other sources, and some have leadership roles in other MD-PhD programs. While our program has had a long history of success, we are cognizant of the future challenges facing our trainees to achieve success in careers as physician-scientists involved in basic and translational research. To help them reach the highest levels of success, our goals for the next 5 years include: 1) Providing our trainees with academic programs that integrate basic science with clinical medicine; 2) Providing our trainees with a new career mentorship program that features successful physician-scientists; 3) Build on existing programs to enhance camaraderie and instill confidence that the physician-scientist pathway is viable and worthwhile; 4) Working with our PSTP colleagues to further enhance the likelihood of success of our students; 5) Working with our institutional stakeholders to reduce time to degree without sacrificing necessary rigor, and 6) Building on our recent success in recruiting a diverse cohort of individuals who will be well trained to be leaders in the discovery and application of ground-breaking research and innovative patient care.